Flat-bottomed tank with leak-proof coating

The present invention relates to a flat bottom container with leak-tightening lining for storing water endangering media, and a method for supplying a single-bottomed container, mainly for subsequent supply, with a leak-proof lining. The essence of the present invention is that the leakage protective coating consisting of at least one pressure-resistant cavity forming part (3) and said plastic foil (4) is provided at a distance from the reservoir bottom (1) in the outer boundary region of the container wall (2) or the reservoir bottom (1) (5), in which the grooving structure (5) consists of inward protruding pins arranged at the same height in the container wall or the container wall (2) at defined distances at which distances are drawn, or by means of a fixed edge , a circumferential rim ring (19), (4) and the plastic foil (4) and the inner wall (2) of the plastic foil (2) or the flange ring (2), and the elastic sealing strips around the rim ring (2) with a fixing pin or flanged ring. HE